JAVA設(shè)計(jì)模式之簡(jiǎn)單粗暴學(xué)建造者模式

將一個(gè)復(fù)雜對(duì)象的構(gòu)建和它的表示分離摹迷，使得同樣的構(gòu)建過(guò)程可以創(chuàng)建不同的表示。

建造者有以下角色：

• 導(dǎo)演類：負(fù)責(zé)安排已有模塊的安裝順序孤荣，最后通知建造者開始建造甸陌。
• 建造者：抽象Builder類，用于規(guī)范產(chǎn)品的組建盐股。
• 具體建造者：實(shí)現(xiàn)抽象Builder類的所有方法钱豁，并返回建造好的對(duì)象。
• 產(chǎn)品類疯汁。

簡(jiǎn)單示例

1牲尺、產(chǎn)品類

public class MobilePhone {

    //手機(jī)屏幕
    private String screen;
    //電池
    private String battery;
    //話筒
    private String microphone;
    //聽筒
    private String phoneReceiver;
    //機(jī)身
    private String phoneBody;

    public String getScreen() {
        return screen;
    }

    public void setScreen(String screen) {
        this.screen = screen;
    }

    public String getBattery() {
        return battery;
    }

    public void setBattery(String battery) {
        this.battery = battery;
    }

    public String getMicrophone() {
        return microphone;
    }

    public void setMicrophone(String microphone) {
        this.microphone = microphone;
    }

    public String getPhoneReceiver() {
        return phoneReceiver;
    }

    public void setPhoneReceiver(String phoneReceiver) {
        this.phoneReceiver = phoneReceiver;
    }

    public String getPhoneBody() {
        return phoneBody;
    }

    public void setPhoneBody(String phoneBody) {
        this.phoneBody = phoneBody;
    }

    @Override
    public String toString() {
        return "MobilePhone{" +
                "screen='" + screen + '\'' +
                ", battery='" + battery + '\'' +
                ", microphone='" + microphone + '\'' +
                ", phoneReceiver='" + phoneReceiver + '\'' +
                ", phoneBody='" + phoneBody + '\'' +
                '}';
    }
}

2、抽象建造者

public interface IBuildMobilePhoneBuilder {
    /**
     * 建造手機(jī)屏幕
     */
    void buildScreen();

    /**
     * 建造手機(jī)電池
     */
    void buildBattery();

    /**
     * 建造手機(jī)聽筒
     */
    void buildMicrophone();

    /**
     * 建造手機(jī)話筒
     */
    void buildPhoneReceiver();

    /**
     * 建造手機(jī)機(jī)身
     */
    void buildPhoneBody();

    MobilePhone build();
}

3、具體建造者

public class IPhoneXBuilder implements IBuildMobilePhoneBuilder {
    private MobilePhone mobilePhone;

    public IPhoneXBuilder(){
        mobilePhone =  new MobilePhone();
    }

    /**
     * 建造手機(jī)屏幕
     */
    @Override
    public void buildScreen() {
        mobilePhone.setScreen("OLED顯示屏");
    }

    /**
     * 建造手機(jī)電池
     */
    @Override
    public void buildBattery() {
        mobilePhone.setBattery("2700mAh電池容量");
    }

    /**
     * 建造手機(jī)聽筒
     */
    @Override
    public void buildMicrophone() {
        mobilePhone.setMicrophone("聽筒");
    }

    /**
     * 建造手機(jī)話筒
     */
    @Override
    public void buildPhoneReceiver() {
        mobilePhone.setPhoneReceiver("話筒");
    }

    /**
     * 建造手機(jī)機(jī)身
     */
    @Override
    public void buildPhoneBody() {
        mobilePhone.setPhoneBody("iphoneX機(jī)身");
    }


    /**
     * 創(chuàng)建手機(jī)
     * @return
     */
    public MobilePhone build(){
        return mobilePhone;
    }
}

4谤碳、導(dǎo)演類

public class Director {
    /**
     * 建造一部手機(jī)
     * @param buildPhone
     * @return
     */
    public MobilePhone createMobilePhone(IBuildMobilePhoneBuilder buildPhone){

        buildPhone.buildBattery();
        buildPhone.buildMicrophone();
        buildPhone.buildScreen();
        buildPhone.buildPhoneReceiver();
        buildPhone.buildPhoneBody();

        return buildPhone.build();
    }
}

• 屏蔽產(chǎn)品內(nèi)部組成細(xì)節(jié)溃卡。
• 具體建造者類之間相互獨(dú)立，容易擴(kuò)展蜒简。
• 會(huì)產(chǎn)生多余的建造者對(duì)象和導(dǎo)演類瘸羡。

另一種實(shí)現(xiàn)方式：

public class Student {

    String name = null;
    int number = -1;
    String sex = null;
    int age = -1;
    String school = null;

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", number=" + number +
                ", sex='" + sex + '\'' +
                ", age=" + age +
                ", school='" + school + '\'' +
                '}';
    }

    //構(gòu)建器，利用構(gòu)建器作為參數(shù)來(lái)構(gòu)建Student對(duì)象
    public static class StudentBuilder {
        String name = null;
        int number = -1;
        String sex = null;
        int age = -1;
        String school = null;

        public StudentBuilder setName(String name) {
            this.name = name;
            return this;
        }

        public StudentBuilder setNumber(int number) {
            this.number = number;
            return this;
        }

        public StudentBuilder setSex(String sex) {
            this.sex = sex;
            return this;
        }

        public StudentBuilder setAge(int age) {
            this.age = age;
            return this;
        }

        public StudentBuilder setSchool(String school) {
            this.school = school;
            return this;
        }

        public Student build() {
            return new Student(this);
        }
    }

    public Student(StudentBuilder builder) {
        this.age = builder.age;
        this.name = builder.name;
        this.number = builder.number;
        this.school = builder.school;
        this.sex = builder.sex;
    }
}

  @Test
    public void thatTest(){
//        System.out.println(new Director().createMobilePhone(new IPhoneXBuilder()));
        Student a = new Student.StudentBuilder().setAge(13).setName("LiHua").build();
        Student b = new Student.StudentBuilder().setSchool("sc").setSex("Male").setName("ZhangSan").build();
        System.out.println(a);
        System.out.println(b);
    }